The top graph makes it seem much more dramatic than it is.
Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage.
Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount.
The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. And the two big factors are the energy required to do the refining and delivering the fuel from the refinery to the gas station. Shipping the crude from the oil field to the refinery is a factor, but a small one in comparison.
This 40% is the main reason why driving an EV emits less carbon than driving an equivalently sized gas vehicle even if you're topping up that EV with the dirtiest electricity you can find.
P.S. maritime shipping typically uses very dirty fuel. We'll probably notice the reduction in sulfur pollution more than the reduction in CO2.
P.P.S 3% of a very large number is still itself a large number, so it's still worth looking for solutions.
Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping?
I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to transportation using clean energy is an obvious benefit of EVs. The “dirty electricity” angle is less obvious to me.
In an EV about 90% of the energy used is converted into motion. About 10% goes to heat. [1][3]
In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2]
In other words electric motors are about 3 times more efficient than ICE.
[1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy if you need heat.
[2] ICE motors vary in effeciency a lot. 20-30% is typical. The Carnot formula comes into play here.
[3] because there is so little heat generated, the cooling systems (EVs still have them) are much smaller. And simpler (for example, no fan, 'cause there's no heat when standing still.)
>> The “dirty electricity” angle is less obvious to me.
A power plant typically gets about 60% of energy from a fossil source. A car does zbout 30%. So even if the electricity comes from say coal, it's still more efficient than buying gas in a car engine.
Of course, these days, it's likely that a substantial portion (up to 100% in some cases) is not "fossil electricity" but rather comes from solar, wind, hydro etc. Ie "clean" electricity.
The important driving factor is that generation becomes more efficient when you can use natural gas to turn turbines directly and then capture the waste heat to boil water and turn turbines with steam. This is called combined cycle if you want to google it to learn more.
Another thought exercise, if generating electricity with fossil fuels wasn’t more efficient at scale, why would we bother building a grid in the first place? Every house would just have a gas generator.
The headline is only surprising if shipping is the majority of fuel use.
It isn’t. In the limit, if it were 100% of fuel use, then we’d be burning 1.2 gallons of fossil fuel to deliver 1 gallon, which clearly wouldn’t work.
A much better question is “what percentage of the embodied carbon for this good is from freight shipping”? The answer is almost always very low because last mile shipping dominates, and so does manufacturing the item. For fossil fuel, those things dominate, and so does the step where the customer burns the fuel.
Basically, the entire article is confused because it doesn’t start with the fossil fuel equivalent of Amdahl’s Law.
To further give context: the article is saying that most of the fuel transported around is done for long distances, so when something removes fuel use in the consumer side it has a double dip effect: less fuel consumed and less fuel used to transport the fuel, since long fuel supplies route diminish. It's a third order of thinking and that's why it's confusing. The article then argues that reducing that consumption in the buyers side is more effective:
> This is the part that fuel-first narratives tend to miss. In a serious energy transition, coal demand falls, oil demand falls, and gas demand falls. That means fewer bulk carriers and tankers moving fossil energy around the world. The maritime sector does not have to find a one-for-one replacement fuel for all of that work, because a material share of the work should disappear.
I would argue that chipping away at all three sides of the equation reducing the amount of fuel used, the amount of fuel used for transport and transporting things using other that fuel are worth pursuing.
I swear to God, I've read the article twice and I've read the comments replying to your question and I still have no idea.
I think the problem is that, for any given sentence, it is unclear whether the author is talking about the fuel a ship is burning to move its cargo, or fuel that the ship is transporting to a destination.
I do understand that the article is making some kind of distinction between the two, but it is so terribly written that it's just impossible to figure out which one it's talking about at which point. Or at least I certainly don't care to waste my time "solving" the article like it's some kind of linguistic puzzle.
I'm not sure I've ever come across an article that needed an editor to improve its clarity more than this one.
It's saying that 40% of the tons of cargo loaded onto ships is fossil fuels, but this makes up about 50% of ton-miles, because fossil fuels travel further on average than other cargo. Not the easiest headline to correctly parse.
I read this and another half-dozen replies to the parent comment (but not the article, of course...) and was still confused. This comment was the clearest to getting me to understand it.
Example contributors as I presently understand it:
- we transport fossil fuels further around world (i.e. Middle East to the US)
- we transport most other goods some shorter distances
- iron ore transport is "up there" with fossil fuels; high ton-miles of transport.
And of course the cost of transport for a good is a function of distance, a la the rocket equation mentioned in other comments.
And the article is focused on making this point in the context of the effect of reduced demand for fossil fuels and steel (iron ore) on maritime demand. (which is interesting, and totally not what the article title was leading my brain to think about)
Edit: And then I went and actually looked at the figure at the top of the article; guess the real topic is yet a different framing than what I comment on above!
From the fucking article: Fossil fuel cargoes travel long distances in very large flows, so their decline removes more than a proportional share of cargo mass. It removes a larger share of the ocean work and the fuel burned to do that work.
And if I can get on my soapbox. This same problem (carrying fuel to feed the transportation unit) is well studied in medieval England because it was one of the main determinants of where cities and castles were placed (albeit unknowingly at the time). And we see what happened in England when they were able to get out from under feeding oxen.
> It removes a larger share of the ocean work and the fuel burned to do that work.
Sure, but as long as ratio of fuel moved:fuel used is good enough, people won't care (as demonstrated by historical data). This isn't an argument that leads to change. For those not already convinced of the climate crisis, you'll need to lean on economics.
That is orthogonal to the point. Shipping is considered a hard industry to reduce CO2 emissions, like aviation, but unlike aviation, 50% of the distance ships are traveling are just delivering fuel. So solving non-shipping fuel use solves nearly half of shipping fuel use. The remaining uses of shipping are also much more tractable to electrify.
It’s also a clue as to why there’s such serious political opposition to wind and solar and to some extent nuclear for electric generation.
Point of use generation is disruptive to many industries… not just petroleum but automotive, trucking, various services that serve both, etc. There’s a significant portion of the population employed by schlepping oil around and doing things with it to support those activities.
Are you making a reference to the Tyranny of the Rocket Equation? The Earth's gravity is so large that it's almost at the limit of chemical rockets. A typical rocket is 90% propellant by mass, 8% structure and 2% payload.
Yes it’s a reference to the tyranny of the rocket equation. The same principle applies to wagon logistics because the animals and driver are constantly eating the food the wagons carry.
FTA: "We may call this problem the ‘tyranny of the wagon equation’ as a number of readers have noticed the similarity to the tyranny of the rocket equation."
I’ve wondered if this belongs on the Fermi paradox pile. Many biospheres may be more massive planets that are so hard to get off that a space enterprise never starts.
Meanwhile lighter planets might have trouble holding onto atmospheres.
There is no mention of the amount of fuel used to transport the fuel in the article. From what I know it’s a tiny fraction: boats are efficient at transporting stuff (slowly)
> Fossil fuels are roughly 40% of maritime tonnage, but in the model they represent about half of maritime freight energy because coal, oil, and gas are mostly long-haul bulk trades. Moving a ton of scrap metal a short distance and moving a ton of oil or LNG across oceans are not the same transport-energy problem, even if both show up as one ton in a cargo table.
as being exactly what was being talked about... more fuel is spent on transporting fuel due to distance it travels.
but your comment made me re-visit (i.e. more closely skim...) the article, and it's really about: "as the demand for fossil fuels is projected to decrease, (1) less long-haul shipping is needed and (2) a greater fraction of shipping will be short-haul, which will be practical for other types of freight fueling (i.e. what's shown in the figure at the top of the article)
I have no sense of how realistic the figure is. For example, I don't know the current projections for decline of fossil fuel demand over ?? year timeframe.
It’s trying to say what if we didn’t have to haul energy around from place to place but generate it closer to consumption - we could move more useful stuff instead.
Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage.
Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount.
The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. And the two big factors are the energy required to do the refining and delivering the fuel from the refinery to the gas station. Shipping the crude from the oil field to the refinery is a factor, but a small one in comparison.
This 40% is the main reason why driving an EV emits less carbon than driving an equivalently sized gas vehicle even if you're topping up that EV with the dirtiest electricity you can find.
P.S. maritime shipping typically uses very dirty fuel. We'll probably notice the reduction in sulfur pollution more than the reduction in CO2.
P.P.S 3% of a very large number is still itself a large number, so it's still worth looking for solutions.
I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to transportation using clean energy is an obvious benefit of EVs. The “dirty electricity” angle is less obvious to me.
In an ICE engine about 30% of the energy becomes motion. About 70% is heat.[2]
In other words electric motors are about 3 times more efficient than ICE.
[1] an interesting side effect of this is that in cold climates you can't just harvest waste heat to heat the cabin (or batteries. ) So you end up using some battery energy if you need heat.
[2] ICE motors vary in effeciency a lot. 20-30% is typical. The Carnot formula comes into play here.
[3] because there is so little heat generated, the cooling systems (EVs still have them) are much smaller. And simpler (for example, no fan, 'cause there's no heat when standing still.)
If you charge at home it gets less. If you have solar at home it approaches zero.
Yes, the cost of the car itself is a factor, but even there prices are dropping all the time.
Plus you can also factor in maintenance costs. The cost of ownership of an ev, from a service and maintenance point of view is a lot lower.
[1] ymmv somewhat. Although electricity prices vary a lot, so do gas prices. The 50% saving (at worst) is a pretty good rule of thumb though.
A power plant typically gets about 60% of energy from a fossil source. A car does zbout 30%. So even if the electricity comes from say coal, it's still more efficient than buying gas in a car engine.
Of course, these days, it's likely that a substantial portion (up to 100% in some cases) is not "fossil electricity" but rather comes from solar, wind, hydro etc. Ie "clean" electricity.
The important driving factor is that generation becomes more efficient when you can use natural gas to turn turbines directly and then capture the waste heat to boil water and turn turbines with steam. This is called combined cycle if you want to google it to learn more.
Another thought exercise, if generating electricity with fossil fuels wasn’t more efficient at scale, why would we bother building a grid in the first place? Every house would just have a gas generator.
It isn’t. In the limit, if it were 100% of fuel use, then we’d be burning 1.2 gallons of fossil fuel to deliver 1 gallon, which clearly wouldn’t work.
A much better question is “what percentage of the embodied carbon for this good is from freight shipping”? The answer is almost always very low because last mile shipping dominates, and so does manufacturing the item. For fossil fuel, those things dominate, and so does the step where the customer burns the fuel.
Basically, the entire article is confused because it doesn’t start with the fossil fuel equivalent of Amdahl’s Law.
> This is the part that fuel-first narratives tend to miss. In a serious energy transition, coal demand falls, oil demand falls, and gas demand falls. That means fewer bulk carriers and tankers moving fossil energy around the world. The maritime sector does not have to find a one-for-one replacement fuel for all of that work, because a material share of the work should disappear.
I would argue that chipping away at all three sides of the equation reducing the amount of fuel used, the amount of fuel used for transport and transporting things using other that fuel are worth pursuing.
"40% of horse-drawn carriage cargo is hay, but 50% of what we feed horses is hay".
So what?
I think the problem is that, for any given sentence, it is unclear whether the author is talking about the fuel a ship is burning to move its cargo, or fuel that the ship is transporting to a destination.
I do understand that the article is making some kind of distinction between the two, but it is so terribly written that it's just impossible to figure out which one it's talking about at which point. Or at least I certainly don't care to waste my time "solving" the article like it's some kind of linguistic puzzle.
I'm not sure I've ever come across an article that needed an editor to improve its clarity more than this one.
Example contributors as I presently understand it:
- we transport fossil fuels further around world (i.e. Middle East to the US)
- we transport most other goods some shorter distances
- iron ore transport is "up there" with fossil fuels; high ton-miles of transport.
And of course the cost of transport for a good is a function of distance, a la the rocket equation mentioned in other comments.
And the article is focused on making this point in the context of the effect of reduced demand for fossil fuels and steel (iron ore) on maritime demand. (which is interesting, and totally not what the article title was leading my brain to think about)
Edit: And then I went and actually looked at the figure at the top of the article; guess the real topic is yet a different framing than what I comment on above!
And if I can get on my soapbox. This same problem (carrying fuel to feed the transportation unit) is well studied in medieval England because it was one of the main determinants of where cities and castles were placed (albeit unknowingly at the time). And we see what happened in England when they were able to get out from under feeding oxen.
Sure, but as long as ratio of fuel moved:fuel used is good enough, people won't care (as demonstrated by historical data). This isn't an argument that leads to change. For those not already convinced of the climate crisis, you'll need to lean on economics.
Point of use generation is disruptive to many industries… not just petroleum but automotive, trucking, various services that serve both, etc. There’s a significant portion of the population employed by schlepping oil around and doing things with it to support those activities.
The Tyranny of the Wagon
Meanwhile lighter planets might have trouble holding onto atmospheres.
Fossil fuels are 40% of freight tonnage, but transporting them fuels is responsible for 50% of the total freight fuel consumption.
I assume 99% of freight uses fossil sources as fuel.
> Fossil fuels are roughly 40% of maritime tonnage, but in the model they represent about half of maritime freight energy because coal, oil, and gas are mostly long-haul bulk trades. Moving a ton of scrap metal a short distance and moving a ton of oil or LNG across oceans are not the same transport-energy problem, even if both show up as one ton in a cargo table.
as being exactly what was being talked about... more fuel is spent on transporting fuel due to distance it travels.
but your comment made me re-visit (i.e. more closely skim...) the article, and it's really about: "as the demand for fossil fuels is projected to decrease, (1) less long-haul shipping is needed and (2) a greater fraction of shipping will be short-haul, which will be practical for other types of freight fueling (i.e. what's shown in the figure at the top of the article)
I have no sense of how realistic the figure is. For example, I don't know the current projections for decline of fossil fuel demand over ?? year timeframe.